Proportional pressure-regulating valves are used, for example, in mobile working machines for the electrohydraulic controlling of clutches. When actuated or engaged, these clutches are initially pressurized with fluid pressure until the respective clutch disk reaches or contacts the respectively associated contact surface. The clutch pressure required to overcome the spring forces assumes comparatively small values below 2 bar. An additional increase in the clutch pressure results in the kind of forces on the clutch disks or clutch linings that then enable a torque to be transmitted by friction.
In the case of directly controlled proportional pressure-regulating valves, magnets having large working strokes are used to open or release a maximally large flow cross section as an opening cross section for the respective fluid connection. If these large and comparatively cost-intensive magnets were to be replaced by smaller cost-effective magnets as actuating devices with equal force, the linear power-stroke range would have to be shortened accordingly. Otherwise, this replacement would inevitably mean that when actuating the actuation device, such as when energizing an electromagnet, to open the second fluid connection from the supply connection to the working connection, a large spring force or restoring force would have to be initially overcome, and that the linear P-I characteristic curve of the proportional pressure-regulating valve would be achieved in a kind of “jump start” when the spring force or restoring force is exceeded as a result of the magnetic force. This situation could result in a “jerky”, delayed start-up of the working machine, which is undesirable for the working machine in mobile applications.